29... a3a5 The queen is forced back. 30. b5f1  30... g8g7  31. e4d2 After this move Black gains a clear advantage. Nakamura probably realized by now that he had no advantage and that it would be nearly impossible to play for a win. It was better to advance the kingside with 31.h4 or g4 or to simply play something like 31.Kg2. 31... d5c3 